Under-house Excavation in Sunshine Coast
A dig-out lowers the ground under a raised house to win usable head height. It is priced as a project rather than a rate, and the digging itself is rarely the largest part of it.
What under-house excavation in Sunshine Coast actually involves
A full under-house dig-out for additional living space typically runs A$15,000 to A$50,000 or more, depending on volume and where the spoil goes. A general Brisbane-region excavation rate for the raw digging is roughly A$30 to A$80 per cubic metre — a generic rate rather than a house-raising-specific one, but the unit the bulk of the cost scales on. The gap between those two figures is everything else a dig-out requires: retaining to hold the excavated edge, drainage, and disposal of spoil that often cannot be spread on site.
What a dig-out actually costs
Access is the variable that most often decides whether a dig-out is viable at all. Machinery has to reach the underfloor space and spoil has to leave it, and on a tight coastal block or a steep hinterland one that can mean smaller plant, more handling, and a materially higher cost per cubic metre than the headline rate suggests.
Drainage is not an afterthought on this coast, it is the design. Lowering the floor of a space on the flat coastal plain — where the Bureau of Meteorology describes flooding as longer in duration than in the hinterland — means creating a low point in ground where water already leaves slowly. Where the property sits in a designated flood hazard area, the council flood information search returns the defined flood level and freeboard for the site, and those numbers should be in hand before anyone decides how far down to dig.
What under-house excavation costs in Sunshine Coast
Full under-house dig-out A$15,000–50,000+, depending on volume and spoil disposal. Raw excavation runs roughly A$30–80 per cubic metre — a generic Brisbane-region rate, not house-raising-specific. Retaining, drainage and disposal account for most of the difference.
Full price ranges for every job type are on the pricing page. A firm price comes from a site visit — call (07) 5227 8232 or use the quote form.
Under-house Excavation in Sunshine Coast — common questions
How much head height can I gain?
It depends on how high the house sits now and how far down you can go before drainage or footings become the constraint. A dig-out is usually paired with a raise for that reason — raising gains height from above, excavating gains it from below.
Why is retaining always in the quote?
Because an excavated edge under a house has to be held. Retaining, drainage and spoil disposal are the reason a dig-out costs multiples of the raw per-cubic-metre digging rate.
Can spoil be spread on my block?
Sometimes on larger hinterland blocks, rarely on smaller coastal ones. Where it cannot, disposal becomes a real line item and it scales with volume.
Under-house Excavation by suburb
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